It had to be the bullpen. Good grief, the offence and rotation were gangbusters, right? But could those fickle relievers complete the circle? Doubts abounded.

So here we are, a week into June, and the bullpen has been the one consistent cog in the Blue Jays’ sputtering machine. It was again in a 6-1 win over the Texas Rangers on Friday night, in which the relief corps worked five scoreless innings, allowing but a solitary single.

The starter was a reliever, too. Esmil Rogers, a workhorse out of the bullpen until two weeks ago, lurched through the first inning before settling into a six-strikeout groove. In his two emergency starts, Rogers has allowed one run in 7 1/3 innings, with 10 strikeouts to boot.

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On Saturday, the ‘pen will add another member, whose name is better known to Toronto fans than some of the incumbents. Dustin McGowan will continue his bid for an improbable comeback when he is activated from the disabled list. He will come off a rehab stint that lasted 10 games this year and close to five years after shoulder surgery first shut him down.

The Texas run came in the first. Rogers left after 73 pitches, bringing on a relay squad of Aaron Loup, Neil Wagner, Brett Cecil and Steve Delabar. They faced the minimum 15 hitters. That only hit, off Wagner, was erased on a double play.

The Friday-night ensemble performance was a small blessing for a team whose rotation has been plagued by instability and injury all season. More than 36,000 customers also got a kick out of the Jays’ four-run sixth inning, which broke open a tight game.

Blue Jays relievers have worked 17 2/3 consecutive innings without yielding a run. In 16 games since May 21, their combined ERA is 2.20.

“They’ve been on a nice little roll,” manager John Gibbons said. “We’ve got some weapons out there.”

One of the newer weapons is Wagner, the 29-year-old right-hander who now has allowed no runs in five outings since his May 29 promotion from Triple-A Buffalo. For his 1 1/3 near-perfect innings against Texas, he earned his first big-league win.

Wagner had a 5.49 ERA in the minors last year before signing with Toronto in the offseason. He scrapped his curveball over the winter and focused on his slider and split-fingered pitch to complement a mid-90s fastball.

“I worked pretty hard this offseason on changing what I felt I needed to change from last season to this season,” he said. The changes, he said, have helped him “pound the zone more and repeat [his] delivery better.”

Gibbons said he wanted to confine Rogers to 80 pitches. Next time – and there will be a next time, the manager said – Rogers will work with a longer leash.

Rogers, who allowed three hits, said his slider was a big factor in his success. He has clearly embraced his new role.

“They give me the opportunity. I try to do my best and get another opportunity,” he said.

Nick Tepesch, the Rangers’ rookie starter, retired the first nine Jays he faced before Melky Cabrera led off the fourth with a homer. The score remained tied until the sixth, when Edwin Encarnacion’s two-run double highlighted a four-run frame.

Cabrera had three hits, including an RBI single in the seventh. He has hit safely in 24 of his past 30 games, batting .336 with 12 extra-base hits and 12 multi-hit games.